module Jekyll::Filters

def where(input, property, value)

Returns the filtered array of objects

their `#inspect` string object.
Cannot be an instance of Array nor Hash since calling #to_s on them returns
value - the desired value.
property - the property within each object to filter by.
input - the object array.

Filter an array of objects 
def where(input, property, value)
  return input if !property || value.is_a?(Array) || value.is_a?(Hash)
  return input unless input.respond_to?(:select)
  input    = input.values if input.is_a?(Hash)
  input_id = input.hash
  # implement a hash based on method parameters to cache the end-result
  # for given parameters.
  @where_filter_cache ||= {}
  @where_filter_cache[input_id] ||= {}
  @where_filter_cache[input_id][property] ||= {}
  # stash or retrieve results to return
  @where_filter_cache[input_id][property][value] ||= input.select do |object|
    compare_property_vs_target(item_property(object, property), value)
  end.to_a
end